The present invention relates to a communication processing device, a communication processing method, and a computer program. More particularly, the present invention relates to a communication processing device, a communication processing method, and a computer program, wherein with master-slave type small-scale wireless communication processing, setting a mobile terminal of a user as a master and an access point which the mobile terminal can access as a slave, enables the mobile terminal to perform communication using access points as multiple slaves, so data processing using resources connected to two or more access points can be performed.
In recent years, portable personal computers, cell phones, and so forth have come into widespread use, and many users carry small devices having communication functions and information processing functions, and connect to networks outdoors or at other locations to perform communication via network. In such a mobile computing environment, it is assumed that devices which are connected to a network and receive services via the network, such as portable communication terminals, PDAs, mobile computers, or the like, are nodes which move. In order to use a moving node, it is necessary that no communication interruption due to moving of the node occurs.
In various fields, techniques for realizing ubiquitous computing, which is being proposed as an environment where users can readily connect to a network at any time and any place, is being researched and developed. As one of the techniques, there has been an argument over making a certain space intelligent. For example, a system or the like wherein two or more access points (AP) distributed and disposed in movement space of a user track the movement of users, and network devices work in conjunction with the movements of the user, has been proposed.
However, such a user tracking system works effectively when the range of movement of the user is restricted, and it is difficult to build a user tracking processing system throughout all space when the range of movement of the user is not restricted. Accordingly, there is the problem of scalability. Also, in the event of performing user management in increments of a predetermined space, there is another problem in that privacy of a user who uses resources of a predetermined space is not protected. For example, there is the risk that a resource administrator in a certain space might record contents information used by a user.
On the other hand, as a system employing the existing infrastructure, a personal communication service dispersion system which employs various existing various communication networks by switching over as appropriate, has been proposed (for example, Patent Document No. 1: Japanese Unexamined Patent Application Publication No. 8-56263). The system disclosed in Patent Document No. 1 ais a system which enables integrating and using different networks such as mail services or phone services or the like.
The system disclosed in this Patent Document No. 1 comprises a resource control program which manages various hardware resources such as a PC connected to a physical network, a service control program which controls a physical network for each user ID as user identification information, and a service control device having a directory for searching each of the control programs and hardware, and in the event of performing communication processing wherein a user inputs a user ID and uses resources for example, the service control device performs a directory search, and performs transfer destination search for input signals from the user, routing processing, and so forth.
However, with a configuration described in the Patent Document, a resource control program, a service control program, and a service control device having a directory for searching these control programs and hardware need to be set for each predetermined hardware resource, so there is the problem of scalability as well. Also, processing base on input of a user identifier is required, so there is the problem of user privacy protection.
Meanwhile, as a short-distance communication control method, a master-slave type communication method such as BLUETOOTH for example, has come to be widely employed in these days. In such a master-slave type communication control method, a master for performing communication intermediary processing within a small-scale network (pico-network) is disposed, and a communication device (slave) in a pico-network can perform communication via the master. In such a master-slave type communication control method, entering a newly participating slave to a pico-network is easily carried out, and breakaway from the pico-network is also easily carried out, accordingly, it can be said that this method is suitable for communication with mobile terminals.
For example, a wireless communication system using BLUETOOTH has the advantage that there is no directivity and transparency is high, as compared with infrared data communication methods such as the conventional IrDA (Infrared Data Association). Hence, in the event of employing communication with high directivity such as with IrDA, it is necessary to dispose communicating devices so as to face one another appropriately, however, in a communication system such as with BLUETOOTH, there is no positional restriction such as described above.
The standards of BLUETOOTH are managed by BLUETOOTH SIG Inc., and details can be freely obtained by anyone from BLUETOOTH SIG Inc.; for example, with communication using BLUETOOTH, a device detection message for detecting devices which exist in a surrounding area is transmitted by broadcasting from a master device controlling communication.
A master can detect devices which exist in a surrounding area, that is, communicable devices, by response messages transmitted from devices (slaves) which receive this device detection message. Also, in the event of establishing communication with a specific device from the detected devices, the master identifies the device based on identification information of each device included in the response message, and establishes the communication.
In BLUETOOTH, information referred to as a BLUETOOTH device address is assigned to each device as information identifying such a device. This address is unique as to each device, which is employed in various kinds of processing such as administering devices.
Up to seven slaves can belong to one master in the same pico-net in BLUETOOTH communication. All devices belonging to the same pico-net are in a synchronized state on a frequency axis (frequency hopping pattern) and time axis (time slot). Furthermore, a network can be configured by connecting multiple pico-nets as well, which is referred to as a scatter net.
Moreover, in BLUETOOTH, with regard to data sent and received with wireless communication or the communication procedures thereof, specifications referred to as profiles, in which the procedures are arranged for each service, are being formulated, and services which each device can provide are represented according to this profile.
In a PAN (Personal Area Network) profile, a communication method between slaves in a pico-net is regulated so that the pico-net is regarded as one network, and devices belonging to the pico-net configured based on the PAN profile can transmit and receive various kinds of data. Similarly, with regard to scatter nets, stipulations are being planned wherein the scatter net is regarded as one network so as to transmit and receive various kinds of data. This network may be a network based on IP (Internet Protocol), for example.
Now, in the event of configuring such a network, the master obtains information regarding to peripheral devices using the aforementioned device detection messages to determine which device should be a master, and which device should be a slave, or which service should be employed to perform communication, based on user instructions, for example.
Application of a mobile wireless communication terminal of a user to master-slave type wireless communication involves the mobile terminal belonging to various pico-nets and performing communication via the master set in the pico-net.
Suppose, for instance, there is a configuration such as that illustrated in FIG. 1. A mobile terminal 100 which a user owns comprises a control unit 111, memory unit 112, output unit 113, input unit 114, and a communication device 101 for performing short-distance communication such as BLUETOOTH. On one hand, there are access points (AP) 121, 122, and 131 which are disposed in space with a distributed and fixed formation, and various devices (hardware resources) 123 and 132 such as a VTR, printer, PC, and so forth are connected to each access point. Establishing communication with an access point using the mobile terminal 100 allows users to use the devices (resources) connected to the access point.
In such an environment, an access point (AP) 121 fixedly provided is set as a master, and forms a pico-net 120, and in the event that the mobile terminal 100 which the user owns moves into a region of the pico-net 120, the mobile terminal 100 is identified as a slave through predetermined device search processing, thereby enabling communication via the access point 121 which is the master in the pico-net 120 to be performed. Consequently, the device (resource) 123 connected to the access point 121 can be used.
However, the mobile terminal 100 cannot use the device 132 shown in the upper portion of FIG. 1. The mobile terminal 100 does not belong to the pico-net set as a communicable region of the access point (AP) 131 connected to the device 132, so the access point (AP) 131 set as a master does not identify the mobile terminal 100 as its slave.
In order to solve this situation, it is necessary, as shown in FIG. 2 for example, for the mobile terminal 100 to comprise multiple wireless communication devices 151, 152, and 153, and perform communication via each device, so that the mobile terminal 100 can belong to multiple pico-nets and communicate with the access points (AP) set as the master of each pico-net to use the resources connected to each access point in parallel.
In the configuration shown in FIG. 2, the mobile terminal 100 belongs to a pico-net 163 set as a communicable region of the access point (AP) 121, to a pico-net 161 set as a communicable region of the access point (AP) 131, and to a pico-net 162 set as a communicable region of the access point (AP) 122, wherein each access point is assigned to be a master, and the mobile terminal 100 is assigned to be a slave, thereby enabling communication in each pico-net to be performed in parallel. Consequently, connection resources 123 and 132 at each access point can be used in parallel.
However, as described above, in a configuration wherein two or more access points are set as a master, in order to realize communication via each access point, the mobile terminal 100 needs to comprise multiple wireless communication devices 151, 152 and 153, which causes a problem.
FIG. 3 illustrates device and software configuration which a mobile terminal requires. (a) illustrates a configuration of hardware 172 and software 171 which a mobile terminal has to be equipped with in order to perform communication by connection to only one access point as described above with reference to FIG. 1. In the event of performing communication conforming to a specific communication protocol, one communication device for transmitting/receiving data as hardware, and one each of a device driver for controlling a communication device, a network protocol stack for executing processing of a specific communication protocol, and an application program for executing specific processing for transmitting/receiving data, as software, is sufficient for communication processing conforming to a specific protocol.
However, in a configuration shown in FIG. 2, assuming that a different communication protocol is applied to each access point 121, 122, and 131, the mobile terminal needs hardware 172 and software 171 in a configuration shown in FIG. 3(b). In order to perform communication conforming to three types of communication protocols, three communication devices for transmitting/receiving data as hardware are required, and with regard to software, three types of device drivers for controlling each communication device, three network protocol stacks for executing processing of three types of communication protocols, and further an application program for executing specific processing for transmitting/receiving data, are required.
As described above, in the event that two or more access points are set as a master, and each access point performs communication with a different communication protocol, the configuration shown in FIG. 3(b) is required, thereby causing the problem of increased costs for mobile terminals.